ACTRN12619000757112.

Study name	The effect of intermittent fasting on muscle mass in overweight, middle‐aged men
Methods	Randomised controlled trial
Participants	Inclusion criteria 1.Male 2.Age: 35‐55 years 3.BMI: 25‐35 kg/m2 Exclusion criteria 1. Current diagnosis of type 2 diabetes (HbA1C > 6.5% or 48 mmol/mol) 2. Unable to attend the laboratory for visits and adhere to the 3‐day lead‐in diet and 10‐day intervention diet 3. Currently meeting physical activity guidelines (i.e. doing more than 150 minutes of physical activity per week or >10,000 steps per day) 4. Major or chronic illness that impairs mobility or eating/digestion 5. Previous bariatric surgery 6. Shift workers; 7. Smoker (cigarette, e‐cigarette or marijuana) 8. Individuals with strict dietary intake regimens (i.e. vegan, avoidance of principal study foods) 9. Individuals who are currently restricting their dietary intake (i.e. actively trying to diet and lose weight) or participating in regular fasting (defined as fasting >16 hours/day or having completed 12 24‐hour fasts within the past year) 10. Participating in shift work (i.e. >3 hours between 22:00 hours and 05:00 hours for 1 day per week (> 50 days per year)) 11. Not weight stable (>5 kg body weight change over last 3 months) 12. Individuals who do not consume breakfast on at least 5 of 7 days per week (i.e. not eating regular meals) 13. On prescribed medications required to be taken with food in the early morning or late evening or taking other prescribed medications for <3 months 14. On prescribed anti coagulation medications (interfering with muscle biopsy procedures)
Interventions	The study design consists of a randomised, parallel‐group intervention study in 40 overweight, middle‐aged males. The study will involve a 3‐day lead‐in control diet for all intervention groups, after which subjects will be randomised to 10 consecutive days of either the following. 1. Alternate day fasting (ADF: 25 Energy percentage (En%) food ingestion on day 1, 3, 5, 7 and 100 En% food ingestion on day 2, 4, 6, 8 and 10) 2. Continuous energy restriction (CER: daily intake of 62.5 En% of total energy intake) 3. Time restricted eating (TRE: daily intake of 100 En% of total energy intake in an 8‐hour time window) 4. An energy‐balanced control diet (CON: daily intake of 100 En% of total energy intake in a 12‐hour time window, according to current Australian Healthy Eating guidelines comprising a macronutrient intake of 50% En, CHO, 30% En fat and 20% En protein.).
Outcomes	The primary outcome measurement will be muscle protein synthesis rates (%/day) measured using the rate of labelled water (D2O) uptake from the muscle biopsy samples and alanine enrichments in saliva. [Day 0 and Day 11] Body composition assessed by a DEXA scan: fat‐free mass (in % and kg) [Days 0, 4, 8 and 11] Body composition assessed by a DEXA scan: fat mass (in % and kg) [Day s0, 4, 8 and 11] Body composition assessed by a DEXA scan: total body mass (in % and kg) [Dasy 0, 4, 8 and 11] Body water 2H2O enrichment by GC‐MS analyses [muscle biopsies at Day 0 and Day 11; plasma samples at days 0,4,8 and 11; and daily saliva samples from day 0‐11] Free L‐[2,3,3,3‐2H4]‐alanine muscle enrichments by GC‐MS analyses [muscle biopsies at Day 0 and Day 11] Free L‐[2,3,3,3‐2H4]‐alanine plasma enrichments by GC‐MS analyses [plasma samples at day 0,4,8 and 11] Glyacemic control (Freestlye Libre continuous glucose monitoring)[Day 0 to Day 11 (15 minutes time intervals throughout the 10‐day intervention period)] Plasma amino acid concentrations (total amino acid profile measured by LC‐MS)[Day 0, 4, 8 and 11] Plasma gastrointestinal hormone concentrations (PYY, CCK, GLP, GIP and ghrelin)[Days 0, 4, 8 and 11] Plasma glucose concentrations in blood samples analysed by YSI 2900[Days 0, 4, 8 and 11] Plasma insulin concentrations (ELISA) [Days 0, 4, 8 and 11]
Starting date	01/06/2019
Contact information	imre.kouw@acu.edu.au
Notes